MediaWiki:Gadget-collapsibleSidebarSections.js

$(function(){

    // CONFIG section, you can edit this part

    // a list of sections that should be collapsed by default for *all users*.
    // This should be the name of the heading as listed in Mediawiki:Sidebar and is case-sensitive.
    // For example, if you have '* Character_Classes' and you want that section collapsed, add 'Character_Classes' into the brackets below.
    // Separate entries with commas and use underscores instead of spaces.
    // Example list: ['Character_Classes', 'Items', 'External_Links']
    // Please DO NOT add navigation or tb into this list, as they are expected functionality.
    var INITIALLY_COLLAPSED_IDS = [];
	var MIN_ACTIVATION_WIDTH = 721;

    //END CONFIG

    // add the p- onto ids for ease of use, if not present
    INITIALLY_COLLAPSED_IDS.forEach(function(id, index){
        if(!id.startsWith('p-')){
            INITIALLY_COLLAPSED_IDS[index] = 'p-' + id;
        }
    });

	var $portals = $("#mw-panel .vector-menu-portal");

	var setup = function(){
		$portals.each(function(index, el){
			if(window.innerWidth < MIN_ACTIVATION_WIDTH) {
				return;
			}
			var $el = $(el);
			var $id = $el.attr("id");
			if(!$id){
				return;
			}

			// check if this portal should be collapsed
			if(
                // portal is set to be initially collapsed and user has not indicated that they want it open
                (INITIALLY_COLLAPSED_IDS.includes($id) && localStorage.getItem('sidebar_c_'+$id) != "n")
                || // or
                // user has indicated they want this portal collapsed
                (localStorage.getItem('sidebar_c_'+$id) === "y")
                ){
				    $el.addClass('collapsed').find('.vector-menu-content').slideUp(0);
			}
		});
	}
	setup();
	$(window).on('resize', setup);
	$portals.on("click", "h3", function(event){
		if(window.innerWidth < MIN_ACTIVATION_WIDTH) {
			return;
		}
		var $el = $(this).parent();
		var $id = $el.attr("id");
		if(!$id){
			return;
		}

		$el.toggleClass('collapsed');
		if($el.hasClass('collapsed')){ // more consistent between class and slide status.
			localStorage.setItem('sidebar_c_'+$id, "y");
			$el.find('.vector-menu-content').slideUp('fast');
		}
		else{
			localStorage.setItem('sidebar_c_'+$id, "n");
			$el.find('.vector-menu-content').slideDown('fast');
		}
	});
});